1. Field of the Invention
The invention relates to a female quick-connect coupling element and to a quick-connect coupling that can be used for releasably joining together two pipes for pressurized fluid, and that includes, inter alia, such a female element.
2. Brief Description of the Related Art
In the field of releasably joining together pipes through which pressurized fluid flows, it is known that a female coupling element can be used that is provided with controlled locking means for locking a male element in a configuration in which it is fitted into the female element, i.e. in a configuration in which the pipes are interconnected, the male and female elements constituting ends of respective ones of said pipes. A female coupling element is generally provided with a control valve for controlling the flow of the pressurized fluid. It must be possible for said valve to be operated when fluid at very high pressure, in particular liquefied petroleum gas (LPG), is to be fed into a motor vehicle tank at pressures of about 300 bars. For that purpose, it is known that a valve can be used that has two pistons, each of which defines a respective one of the two opposite surfaces in contact with the pressurized fluid. The two pistons that must be operated simultaneously both in the opening direction and in the closure direction are interconnected via a rod that passes through the fluid flow duct and thereby reduces the flow section thereof. The forces exerted by the pressurized fluid on the two pistons put the rod under traction, and the section of said rod must be dimensioned in such a manner as to withstand said forces, making the rod more voluminous.
In addition, in particular if the gas that flows through the coupling is hydrogen, it is known that the action of that gas on a material subjected to traction stress has the effect of reducing the life of the material. This therefore requires the section of the rod to be increased, thereby making it more voluminous.